The present invention relates to a device and a method for data communication between a first host device or a further host device and at least one client device along a shared transmission path. A host device is a host computer (personal computer, workstation), for example, and a client device may be any arbitrary hardware application (e.g., FPGA or ASIC).
FIG. 3 shows a communication system from the applicant of the present application, which is known under the trademark UMRBus. This communication system allows easy transmission of data and/or signals between a host device or host computer (300) and assigned hardware (clients), such as ASICs or FPGAs. Different software applications may communicate with their corresponding hardware applications via independent virtual channels, which use the same hardware interface between the host computer (300) and the client hardware (331, 332, 333). This communication system represents a simple standardized interface between the host computer (300) and at least one client (331, 332, 333). This client (331, 332, 333) may be a software application or a hardware application.
Individual host applications (301, 302, 303), which are indicated in FIG. 1 with “HAPP” (host application), are connected via a host application interface (310) “HAPI” to a host application interface module (312) “HAPIM”. The host application is a program which exchanges data with one or more client application(s) via the host application interface. The host application interface module (312) is a software library which provides multiple functions and commands for access on the communication system. A host application interface HAPI is an interface onto which host applications are placed.
The host application interface module (312) is directly connected to a software interface module (314) “SIM”, which typically corresponds to the device driver specific to the operating system. A host application interface module HAPIM provides the host application interface and transmits data from and to clients in cooperation with the software interface module.
The software interface module (314) is connected via a standardized interface connection (316), PCI or RS232, for example, to a hardware interface module (318) “HIM”. The hardware interface module (318) represents the counterpart to the software interface module (314) in hardware. This hardware interface module (318) may, for example, have a PCI controller and an interface component between the PCI controller and a data bus. The software interface module SIM executes the data exchange between the host application interface module HAPIM and the hardware interface HIM.
An essential feature of the hardware interface module (318) is that it always provides a physical data bus (320) on the side away from the software. This data bus (320) connects the hardware interface module (318) to multiple client application interface modules (341, 342, 343) “CAPIM”. In this case, the data bus (320) represents a ring connection between the client application interface modules (341, 342, 343) linked therein and the hardware interface module (318).
The hardware interface module HIM exchanges data with the software interface module SIM and makes the data bus available to the clients.
Each client application interface module (341, 342, 343) represents a type of node which is incorporated into the physical data bus (320). Each client application interface module (341, 342, 343) is connected via a client application interface (322) “CAPI” to a client application (351, 352, 353) “CAPP”. Each client application interface module (341, 342, 343) has its own address and a type identity and provides the client application interface (322) for the client application (351, 352, 353).
In the device shown in FIG. 3, all of the data communication is controlled by the host computer (300).
In this case, data exchange may only occur between one hardware interface module (318) and one client application interface module (341, 342, 343) at a time. Therefore, communication is only possible between the host computer (300) and the client applications (351, 352, 353), but not within the client applications (351, 352, 353), implemented in the example shown as hardware. In addition, this known device for data communication may not be used in systems having multiple host computers.